Device for connecting catheter and injection tube

ABSTRACT

A device for connecting a catheter to an injection tube, which is provided with an elastic tube into which an open end of the tubular catheter having electrodes disposed at the closed end thereof and also having conductive wires connected to said electrodes and taken out at the open end thereof and an open end of the injection tube having a mechanism for fluid injection at the other end thereof are inserted so that both open ends are connected end-to-end and the conductive wires are taken out through a gap between the elastic tube and the injection tube; and a sealing agent to cover respective surfaces of the catheter, injection tube, and elastic tube which surfaces are coated with an adhesive. The catheter, injection tube, and elastic tube, when coated with an adhesive of high viscosity, are compatible with the hard sealing agent lying thereabove. A casing consisting of half members encloses the sealing agent and the casing increases the strength of the device, whereby the device is prevented from being deformed and prevented from causing leakage of fluid through the gap even when subjected to external force. The device has improved resistance to external pressure. In addition, connection of the conductive wires between the electrodes and the terminals arranged on the side of the casing serves to tightly fix the wires in the sealing agent packed in the case and causes no breakage of the wires, whereby the wires are connected to the external parts through the terminals to thereby provide a device with improved reliability.

TECHNICAL FIELD

This invention relates to device for connecting a catheter havingelectrodes and an injection tube for injecting a liquid into thecatheter.

BACKGROUND ART

A catheter is a hollow tubular instrument which is inserted into thehuman body from the outside. A catheter may be used to inject a liquidinto the body or to extract humor, or it may be is used for maintainingan open state of a passage, and so on.

A catheter having a spherical rubber plug (balloon) attached to itsextreme end is popularly used to effect hemostasis (i.e. used to effectthe arresting of circulation of blood in a blood vessel which ishemorrhaging). It is inserted into the body to a side of a bleedinginternal body portion, for example, a portion of intracerebralhemorrhage which side of the bleeding internal body portion is the sidecloser to the heart. A thermosetting resin is injected into thespherical rubber plug on the extreme end to expand the plug and tothereby stop flow of blood in the blood vessel. In this case, in orderto leave the expanded plug portion on the extreme end of the catheter inthe blood vessel which is used to stop the discharge of blood, theexpanded plug of the catheter is softened and cut off by heat. The heatis generated by supplying a high-frequency electric current carried byleadwires to electrodes which are located on the end portion of thecatheter. In the case of this type of catheter, it is necessary for thecatheter to have a cut portion through which leadwires are led out. Theleadwires connect the electrodes with a high-frequency currentgenerator. Since the thermosetting resin is injected into the plug ofthe catheter through an injection tube under pressure, a pressure proofconnector is used on the cut portion of the catheter to connect thecatheter and the injection tube.

The construction of a prior art connector is as shown in FIG. 2. Anelastic tube 5 (silicone tube) is used to connect catheter 1 which has adiameter of 1.2 mm, and is made of Teflon which is poor in adhesion,with injection tube 4 made of the same material. For improvement inbonding strength of the connections, thereby ensuring resistance to apressure of 15 atm at the maximum instantaneous adhesive 10 having aninterfacial effect and having a low viscosity of about 5 to 10centiPoise is applied to surfaces of the catheter, the injection tubeand the elastic tube, and then epoxy adhesive 6 is applied thereon twoor three times. Leadwires 3, extending from the electrodes, are led outthrough a gap between the elastic tube and the injection tube and areconnected to the high-frequency current generator by alligator clips.

In this conventional connector, the instantaneous adhesive 10 applied tothe surfaces of the catheter, the injection tube and the elastic tubehas a low viscosity and is therefore poor in affinity with hard epoxyresin 6 forming the upper layers, and the connector may be deformed ifan excessive pressure is applied and if the strength of the epoxy resinis insufficient. There is therefore a risk of formation of a gap and,hence, occurrence of liquid leakage. Thus, the conventional connectorentails the problem in terms of being pressure proof. It also entailsthe problem in terms of reliability owing to the risk of disconnectionof the leadwires or the risk of alligator clips coming off since theleadwires are made of fine copper wires having a diameter of 0.05 mm andare connected by the alligator clips.

DISCLOSURE OF THE INVENTION

It is an object of the present invention to provide a device forconnecting a catheter with an injection tube which device has pressureproof properties to prevent liquid leaking at the connecting of thecatheter with the injection tube and which device helps prevent theleadwires from snapping, thereby to be improved in reliability.

The above-described problems can be solved by providing a device forconnecting a catheter and an injection tube comprising (A) an elastictube into which one opening end of the catheter, the catheter being inthe form of a tube, and one opening end of the injection tube, theinjection tube having at its other end a mechanism for injecting aliquid, are inserted and butted against each other. The catheter isclosed at its other end and has electrodes provided on its closed endand has leadwires connected to the electrodes, the leadwires being ledthrough the one end of the catheter and led out of the elastic tube onthe side of the injection tube. The device further comprises (B) asealing material for covering surfaces of the catheter, the injectiontube and the elastic tube which surfaces are coated with an adhesivewherein the adhesive has a high viscosity of about 100 centiPoise, and(C) a casing consisting of half members and having openings throughwhich said catheter and said injection tube extend, and (D) a connectionterminal to which said leadwires are connected.

In this construction, the adhesive applied to the surfaces of thecatheter, the injection tube and the elastic tube has a high viscositysuch as to have good affinity with the hard sealing material forming anupper surface. The casing consisting of half members is provided outsidethe sealing material. The device is thereby improved in strength anddoes not deform such as to form a gap and to cause liquid leakage evenif an external force is applied; it is improved in pressure proofproperties.

Further, the leadwires from the electrodes, which are connected to theconnection terminal provided on a side surface of the casing, are fixedin the sealing material filling the casing so as to be prevented fromsnapping, and are firmly connected to an external unit through theconnection terminal, thus improving the reliability of the device.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a connector which represents anembodiment of the present invention; and

FIG. 2 is a front view of a conventional connector partially inlongitudinal section.

BEST MODE FOR CARRYING OUT THE INVENTION

The present invention will be described below with reference to FIG. 1showing the construction of its embodiment in perspective.

Electrodes 2 are provided on an extreme end portion of catheter 1.Leadwires 3 lead from electrodes 2 on the inside of catheter 1 and areled out of catheter 1 at connecting portions of catheter 1 and injectiontube 4. The connecting portions of catheter 1 and injection tube 4 areinserted into a rubber tube 5 made of, for example, silicone rubber sotht the opening end surfaces of catheter 1 and injection tube 4 abutagainst each other. High-viscosity instantaneous adhesive 10 is appliedto surfaces of catheter 1, injection tube 4 and rubber tube 5, and thecatheter, injection tube and rubber tube are set on one of two halfmembers of a case 12 which said half member has, in its side portions,openings for insertion of the catheter 1 and the injection tube 4, andwhich has a connection terminal 11 for supplying a high-frequencycurrent through leadwires 3. Leadwires 3 are led out of rubber tube 5 onthe side of injection tube 4 and are connected to connection terminals11. Epoxy adhesive 6 is thereafter filled in said one of the two halfmembers of the case 12, and said half member is bonded to the secondhalf member of the case 12. In the thus-constructed connector, there isno risk of the thermosetting resin leaking through the connectingportion even if the resin is injected through the injection tube 4 at apressure of about 15 atm, and no risk of the snapping of the leadwires,and no risk of the disconnection of the high-frequency current suppliedthrough the connector 11. The connector is therefore improved in itsreliability over the prior art connector.

In accordance with the present invention, the catheter and the injectiontube are connected together by an elastic tube and are set on a casing,and the casing is filed with an epoxy resin, thereby improving thestrength of the connection and, hence, the pressure proof properties.

Moreover, the leadwires from the electrodes are connected to theconnection terminal of the connector provided on a side surface of thecasing, and the connection terminals are connected to an external unit,thereby improving the reliability of the connector over the prior artconnector.

What is claimed is:
 1. A device for connecting a catheter and aninjection tube,wherein said catheter is a tubular catheter having anopen end and electrodes disposed at the closed end thereof and havinglead wires connected to said electrodes and taken out at the open endthereof and wherein said injection tube has an open end and has amechanism for fluid injection at the other end thereof, said devicecomprising(1) an elastic tube into which the open end of said tubularcatheter and the open end of said injection tube are inserted so thatboth open ends are connected end-to-end and said conductive wires arelead out through a gap between the elastic tube and the injection tube;(2) a sealing agent to cover respective surfaces of the catheter,injection tube and elastic tube which surfaces are coated with anadhesive wherein said adhesive has a high viscosity and wherein saidcatheter, injection tube and elastic tube, when coated with saidadhesive, are compatible with said sealing agent lying thereabove; and(3) a casing comprising half members wherein a connection terminal isarranged on the side of said casing, and wherein said casing hasopenings through which on one hand said catheter and on the other handsaid injection tube extend wherein the ends of said taken out conductivewires connect to said terminal and said casing serves to tightly fixsaid taken out conductive wires in the sealing agent packed in the case.